The Zone Definition Problem in Location‐Allocation Modeling

A. Stewart Fotheringham, Paul J. Densham, Andrew Curtis

Research output: Contribution to journalArticlepeer-review

62 Scopus citations


Location‐allocation modeling is a frequently used set of techniques for solving a variety of locational problems, some of which can be politically sensitive. The typical application of a location‐allocation model involves locating facilities by selecting a set of sites from a larger set of candidate sites, with the selection procedure being a function of “optimality” in terms of the allocation of demand to the selected sites. In this paper we examine the sensitivity of one particular type of location‐allocation model, the p‐median procedure, to the definition of spatial units for which demand is measured. We show that a p‐median solution is optimal only for a particular definition of spatial units and that variations in the definition of spatial units can cause large deviations in optimal facility locations. The broad implication of these findings is that the outcome of any location‐allocation procedure using aggregate data should not be relied upon for planning purposes. This has important implications for a large variety of applications. 1995 The Ohio State University

Original languageEnglish (US)
Pages (from-to)60-77
Number of pages18
JournalGeographical Analysis
Issue number1
StatePublished - Jan 1995
Externally publishedYes

ASJC Scopus subject areas

  • Geography, Planning and Development
  • Earth-Surface Processes


Dive into the research topics of 'The Zone Definition Problem in Location‐Allocation Modeling'. Together they form a unique fingerprint.

Cite this